Electric alarm



(No Model.)

R. D. 0. SMITH. ELECTRIC ALARM.

No. 416,381. Patented Dec. 3, 1889.

' UNITED STATES PATENT OFFICE ROBERT D. 0. SMITH, OF MISIIAIVAKA, INDIANA. I

ELECTRIC ALARM.

SPECIFICATION forming part of Letters Patent No. 416,381, dated December 3, 18 89.

Application filed July 5, 1889- Serial No. 316,634. (No model.)

To all whom it may concern.-

Be it known that 1, ROBERT D. 0'. SMITH,

- of Mishawaka, in the county of St. Joseph and State of Indiana, have invented a new and useful Electric Tell-Tale; and I do hereby declare that the following is a full and accurate account of the same, reference being bad to the accompanying drawings, in which Figurel is a perspective view of my invention. Figs. 2, 3, 4, 5, and 6 represent modifications.

This invention is particularly applicable to devices for the transmission of power by means of ropes, and the object of it is to detect and give warning of a broken strand of the rope, so that the same may be repairedin time to prevent damage being done by the complete breaking of the rope. I am aware that mechanical devices have' been used for this purpose, the warning being given by the ringing of a bell set in motion by the protruding end of the broken strand. Mechanical devices for this purpose must necessarily be located close to the usual position of the engineer or other attendant or the warning would not be heard; but frequently transmission-ropes do not pass near the stat-ion of any person, and therefore the mechanical contrivance has a limited range of useful ness.

My electrical contrivance obviates all difiiculties of location or usefulness by conveying its warning to any desired place or distance by means of electricity, and if placed in the same battery-circuit with the electric let-off and clutch mechanism, as described in my application forLetters Patent, Serial No. 313,687',it will not only give awarning signal, but will also cause the transmission to be antomatically disconnected from its motor and allowed to stop.

The conveying of power from a prime mover to machinery ata distance by means of a rope is coming largely into use because of the many advantages it possesses over the more cumbersome belt, and under the American system a single endless rope with multiple turns around the terminal wheels to obviate slip. Distance affords but little obstacle, because the only resistance due to distance is the aerial friction of the rope and the journal-friction of the bearing-wheels.

The ropes employed are therefore sometimes several miles in length, and the liability of weak or damaged spots is proportionately increased. In such cases several tell-tales may be placed at difierent points on the same transmission and motion stopped very soon after a fracture occurs. The importance of this early warning will be apparent when it is considered that a break of the rope invariably causes it to depart from the wheels and become entangled somewhere, and then follows destruction in the system until the rope is torn to pieces or the motor stopped.

My invention therefore consists in a battery-circuit, an electric alarm, and a circuitcloser adapted to be closed by the passage of anything adhering to and projecting from the transmitting-rope.

In the drawings, A represents a portion of a rope-wheel, showing the position of the telltale with reference thereto. The wheel A may be either the driver, the driven, or any wheel in the system.

B B represent different parts of the transmitting-rope in the grooves of the wheel A.

O is the tell-tale, which consists of an arm or its equivalent, capable of yielding and transmitting motion to a circuit-closer when engaged by any object adhering to the moving rope. This arm is located close to the face of the wheel and in position to be engaged to any object projecting, say, one inch from the rope. In Fig. 1 this arm is represented as made from a small rod bent in U shape and pivoted at its ends. The transverse central part is located parallel with the face of the Wheel A and within about one inch of the same. It is supported in normal position by a spring D or by weights E-say as shown in Fig. 2. A If the arm C is struck by something moving with the rope, as by a broken and projecting strand, as shown at F, it will move on its pivot and strike the contact-spring G, whereby circuit will be closed on the battery-line and the signal-bell I will be caused to sound. The bell I may be at any convenient distance from the tell-tale, and will naturally be located near the regular station-of the'enginecr or other proper person in authority.

The automatic let-off represented at J and described in my applications for Letters Patent the serial numbers whereof are 313,687 and 315,578 may also be included in the battery-circuit II; but that is optional. If it is so included, then the same electric currentwhich causes the bell I to be sounded will also let off and automatically disconnect the transmission system of the broken rope.

The structure shown in Fig. 1 will only continue contact during the time the moving object is passing, and it is sometimes desirable to cause said contactto continue and the alarm to be continually soundeduntil it shall be heard and receive attention. This is particularly desirable when the person whose business it is to give attention is liable to be temporarily absent from his post. One of .the ways of accomplishing this is by means of two contact-bars K L, curved about the axis of the arm 0, and upon said arm 0 a spring circuit-closer M may be placed. This permits the arm O to have a long range of movement, and being pushed down over the contacts K L a greater or less distance, according to the force of the blow received, it will remain at the point to which it has been moved and the alarm-bell I will continue to ring until the arm C has been reset and the circuit opened again.

A modification of this is shown in Fig. 4c, applicable in places where the available space in front of the Wheel is insufficient for the pivoted arm (J. In this case a single straight arm C is employed, carrying the circuitcloser M. The wire or flexible cord N is connected at one end to the arm C and at the other end to some convenient anchorage. This wire or cord passes in front of the face of the pulley at a distance, say, of about one inch, and it struck by any object moving with the rope it will fly and the arm 0 will be pulled forward and the circuit closed. A spring P may be employed to hold the arm 0 or O in normal position, and also to prevent the automatic return of said arm after closing circuit until properly reset by an attendant. A counter-weight may be added to the arm 0, if desirable.

In Fig. 5 another modification is shown, wherein a simple weight or spring may be substituted for the pivoted arm. N is a wire or cord stretched across the face of pulley A and 111 close proximity thereto and securely anchored at one end, the unanchored end being attached to a weight or spring SlllllGlOllil to maintain the desired tension. The wire or cord passes between contact-springs S S and carries a metallic ball or boss l,which,when said cord or wire is pulled forward,will close the circuit between said springs. If desired, the springs S S may be fashioned to constitute a seat U, to receive and retain said boss.

In Fig. 6 there is a T-shaped arm, instead of the U-shaped of Fig. 1, and the spring D is attached to a crank so adjusted that when the arm 0 is depressed the spring will be carried over the center and will then hold the arm down.

Ilaving described my invention, I claim as new 1. An automatic electrical tell-tale for ropetransmissions and the like, consisting of a pivoted arm or its equivalent placed in front of and close to the face of the pulley, a battery-circuit and an electrical alarm in said circuit, and a circuit-closer actuated by said arm, whereby when the same is engaged by any object moving with the rope said circuit will be closed and the electrical alarm will. be sounded, as set forth.

2. The combination, with the pulley-wheel of a rope-power transmitter, of the batterycircuit II, the tell-tale controlling a circuitcloser in said circuit, said tell-tale being located opposite and close to the face of said wheel, and the let-off J, controlled by said circuit, as and for the purpose set forth.

3. The combination, with the pulley-wheel of a rope-power transmitter, of the batterycircuit H, the tell-tale located opposite to and close to said wheel eontrollinga circuit-closer in said circuit, the let-off J, and the alarmbell I, both in and controlled by said circuit.

4. The combination, with a rope power transmitter, of the battery-circuit II, the pivoted tell-tale provided with a circuit-closer, and two long contact-plates K L, whereby said tell-tale is permitted a long range of motion after closing circuit, substantially as set forth.

R. D. 0. SMITH.

Witnesses:

D. O. FONDA, M. \V. MIX. 

